Associations Between Trimester-specific Gestational Weight Gains And Childhood Obesity At 5-year-old

Backgrounds and Objectives:Maternal gestational weight gain is positively associated with offspring childhood obesity.However,when weight gain in gestation period is related to childhood adiposity are unclear.And there is no weight gain recommendation guideline for Chinese pregnant women,and no unified criterion for evaluating childhood obesity.Our study hoped to assess the status of gestational weight gain and prevalence of childhood overweight/obesity.And we wanted to explore the appropriate range of gestational weight gain in Chinese women,the suitable criteria for childhood obesity in China,and the association between trimester-specific gestational weight gain and offspring childhood obesity.Methods:Our study based on Shanghai Birth Cohort Study.The participants were who were recruited from July 2012 to February 2013 in Xinhua Hospital and International Peace Maternity and Child Health Hospital,and were followed up at 5-year-old from June to August 2017.Maternal pre-pregnancy and trimester-specific gestational weight were extracted by medical record.Offspring height and waist circumference were measured by nutritionists at 5-year-old.The fat mass and percentage body fat was detected by bioelectrical impedance analysis,and the fat mass index was calculated(fat mass/height2,kg/m2).Maternal information was collected by face-to-face questionnaires within 48 hours after delivery,including maternal height,age,parity,education,history of gestational diabetes mellitus,gestational hypertension,preeclampsia/eclampsia,antibiotics use and smoking in pregnancy,paternal height,weight,and family income.Pregnancy outcomes were extracted by medical record,including maternal delivery mode,offspring sex,gestational age,birthweight and length.The duration of breastfeeding was obtained by telephone follow-up at 6 months.We made the following analysis:1.Based on the pregnancy complications and pregnancy outcomes,the receiver operating characteristic curve of the standard of gestational weight gain by Institution of Medicine and Chinese were drawn,and the area under curve was calculated to assess the adequate range of gestational weight gain for Chinese pregnant women.2.Chi-square test was used to compare the distribution differences of overweight and obesity children by criteria of World Health Organization(weight for height and age-specific body mass index),International Obesity Task Force(Asian)(age-specific body mass index)and Chinese children growth reference curve under 7-year-old(weight for height).The differences of children body composition among three criteria were compared by variance analysis and non-parametric test to assess the adequate criteria for Chinese obesity children3.Logistic regression model and linear regression model was used to assess the association between trimester-specific gestational weight gain and childhood overweight/obesity.After stratified by maternal pre-pregnancy body mass index,the association was also assessed.Overweight/obesity of children was defined according to the criteria of International Obesity Task Force,and abdominal obesity was defined if children’s waist-to-height ratio higher than 0.48.The models were adjusted by maternal age,parity,pre-pregnancy body mass index,education,history of gestational diabetes and antibiotic use,smoking during pregnancy,mode of delivery,offspring sex,gestational age,paternal body mass index and annual family incomeResults:1.A total of 488 pregnant women met the inclusion criteria.The average total and first-trimester gestational weigh gain were 16.4±5.5 kg and 2.5±3.3kg,respectively.The average rate of second-and third-trimester gestational weight gain was 0.51±0.18 and 0.57±0.24 kg/week,respectively.Excessive weight gain of pregnant women accounted for 53.9%by IOM and 67.4%by Chinese Standard There were significant differences in the distribution of inadequate,adequate and excessive weigh gain between Institution of Medicine and Chinese standards(P<0.001).The area under curve by Chinese standard in premature birth,low birth weight infants and small for gestational age was larger than area by Institution of Medicine.2.A total of 537 children met the inclusion criteria,with an average body mass index of 15.7±1.7 kg/m2,fat mass of 3.5±1.8 kg,percentage body fat of 17.7±6.6%,and waist circumference of 51.7±4.5 cm.By World Health Organization,the rate of childhood overweight and obesity was 4.7%and 1.1%,respectively.And there was no significant difference in body composition between two groups(P>0.05).By International Obesity Task Force,the rate of childhood overweight and obesity was 18.4%and 7.6%,respectively.And there were significant differences in weight,fat mass,fat mass index,percentage body fat and waist circumference between two groups(P<0.05).By Chinese standard,the rate of childhood overweight and obesity was 15.3%and 6.7%,respectively.And there was significant difference in percentage body fat between two groups(P<0.05)3.301 mother-child pairs met the inclusion criteria.After adjusting for the confounding factors,we found the higher gestational weight gain in first-trimester was associated with a higher risk of childhood overweight/obesity,abdominal obesity,fat mass,fat mass index,percentage body fat and waist circumference(OR:1.40,95%CI:1.06,1.86;OR:1.45,95%CI:1.12,1.87;β:0.35,95%CI:0.17,0.52;β:0.24,95%CI:0.11,0.37;β:1.04,95%CI:0.42,1.65;p:0.87,95%Cl:0.45,1.30,respectively).After stratified by pre-pregnancy body mass index,the associations between first-trimester gestational weight gain and risk of childhood abdominal obesity,fat mass,fat mass index,percentage body fat and waist circumference were found in pregnant women with pre-pregnancy normal weight(OR:1.74,95%CI:1.16,2.60;β:0.41,95%CI:0.15,0.67;β:0.27,95%CI:0.08,0.47;β:1.36,95%CI:0.37,2.36;β:1.06,95%CI:0.44,1.69,respectively).And the associations between third-trimester gestational weight gain and risk of childhood overweight/obesity and abdominal obesity were found in pregnant women with pre-pregnancy overweight/obesity(OR:2.76,95%Cl:1.16,6.55;OR:2.90,95%Cl:1.30,6.48,respectively).Conclusions:1.Excessive weight gain during pregnancy is common in pregnant women.The predicted about pregnancy outcomes associated with inadequate gestational weight gain in Chinese women by Chinese standard was better than Institution of Medicine.However,the guideline of excessive gestational weight gain still needs further study.2.Using the criteria of World Health Organization to evaluate overweight/obesity in Chinese children will underestimate the prevalence of children overweight/obesity.Compared with Chinese growth reference curve,the criteria of International Obesity Task Force(Asian)has a stronger ability to identify obese children from overweight children.And the indicator of International Obesity Task Force is continuous with adulthood,which can have an early warning effect on health3.Weight gain in the first trimester gestation is positively associated with the risk of childhood overweight/obesity,including weight and fat mass.Weight gain should be well controlled and monitored from early pregnancy,and the women with pre-pregnancy overweight/obesity should pay more attention to controlling gestational weight gain in 3rd-trimester.